Process for making shaped bodies from hard substances



. Patented May 3, 19,38

. UNi rEo s'rA rEs P ENT" was time PROCESS. FOR-- MAKING BODIES FBJOMHARD SUBSTANCES Panllilarth, Dusseldorf, Germany No Drawing. Application November 24, 1936,- Se- 4 rial No. 112,606. In. 1935 o orsintering and filling up the pores with melted auxiliary metals. The sintering of a powdered mixture of carbides and auxiliary metals by means or the so-calied compression, under pressure of, for instance, more than 100 kgsJsq; cm.,

15 the sintering temperature remaining below the fusion-point of the auxiliary. metals, isalso known. When treating tungsten carbide by'the above-named processes use is made of the finelypowdered high-carbon carbide, composed main- 1! of WC, obtained by carburizing tungsten powdel", reduced tungstic acid 'or ammonium-paratungstate without melting them. 'Ihe products thus gained have no very great degreeof hard-f ness or or resistance to wear.

-'furnace or between the carbons o! theelectric arc, the resulting products, however, being extremelybrittle and, moreover, verydiillcult to shape. The well-known process of sintering together powdered fusion-products obtained in the ,manner shown above without the use of auxiliary metals also resulted in. the production of shaped 35 bodies or insuflicient resistance and tenacity. 1 These disadvantages and dimculties are avoided and' an extraordinarily hard and wear-resisting --body oi suillcient tenacity is produced by heating in refractory moulds, such as carbon moulds,

molybdenum, titanium,.vanadium, I

zirconium, cerium, silicium, boron, aluminium, beryllium, chromium have provedparticularly suitable m the iormation the hard substance, I

Harder products I 25 were 'obtainedby melting tungsten carbides in carbon crucibles or carbon tubes in anelectric Germany November 29,

's Claims. (01. 75-131) I while the metals of the .irongroup are used as binding or bedding metals, either-by themselves or in the form of their alloys or alloyed, for instance, with vanadium; chromium, tungsten, manganese or molybdenum. By this process the 5 production of shaped bodies is rendered, possible without the use of complicated furnaces .or equipments. It is suflicient to heat the mould under a gas-blast flame, such as an oizy- -acetylene or an oxy-hydrogen flame.

EeampIe.- 70% of a splintered low-carbon tungsten-carbide with a carbon content, of about 3.7%, which has been. melted in the presence of atomic hydrogen, and 30% of bedding material in the form of a crushed tungsten-chromium- ,cobalt alloy are heated together under pressure in an octagonal refractory mould by means of an oxy-acetylene flame'to a temperature beyond the fusion-point of the dding metal. fihaped' bodies made in this w y can be used as cutting inserts for coredrills and deep-well boring tools.

Iclaim: 1. A process for producing shaped bodies of an extremely hard substance with a high, degree I of resistance to wear and 0f tenacity 'made from" carbides, nitrides, silicides, borides; boron and easily fusible auxiliary metals, which Process consists in heating a splintered hard substance obtained by melting material selected from the groupconsisting of carbides, nitrides, silicides and borides of metals or metalloids in the presenceof atomic hydrogen together with binding and bedding material in the form of less diiiicultly fusible metallic substances in a refractory mould, 3 such as a carbon mould, to temperatures above thefusion-point of the binding or bedding metal.

2. A process for producing shaped bodies consistingof a hard substance which process consists in heating a substance selected from the 40 group which consists of carbides, nitrides, sillnium, vanadium, zirconium, cerium, silicium,

boron, aluminium, beryllium, chromium or other similar metals or metalloids forming hard substances which have been melted in the presence of atomic hydrogen'togethe'r with a metal chosen from the iron group toa temperature above the jusing point of the metal selected'from the iron group.

3. A process for'producing sha'pedbodies of a hard substance which process consists in heat-- ing a substance selected from the group which consists of a carbide, nitride, silicide or boride 2 I 5 1 a,11o,'a9e

of an element chosen item the group" consisting of tungsten, molybdenum. titanium,

zirconium, cerium, silicium, boron, aluminium,

beryllium, and chromium which have been melted in the presence of atomic hydrogen together with a, binding agent chosen from the group which vanadium.

consists of iron alioyeiiwith vanadium, chromium, manganese or molybdenum, said heating being at atemnerature above the melting point of the melting agent. i g

PAUL mm 

